Take The Little Bus Up To Rochemolles
Rochemolles is a tiny mountain hamlet about 6.5km from Bardonecchia. I haven't been able to find much information about it but I gather the residents only live there in summer now, since a bad avalanche some years ago killed people.
However, in summer, it's hard to imagine a more beautiful place. It's very, very old, although some of the houses have been restored, and there's a pretty little church (Church of Saint Peter Apostle) which is extremely old and still has some amazing gothic frescoes on the walls.
Most impressive of all, however, are the wonderful views in all directions. Directly behind the village is a mountain and even in late summer there was a waterfall coming down the side of it. As the weather was clear, the views towards Bardonnechia were stunning and in the other direction, more mountains and some in the distance still had snow on the summit.
To visit from Bardonnechia, take Bus No.2 from outside the Railway station. Be careful to check the times of the bus back though as the last one is very early and I can't imagine how you would get down if you missed it.